A series of compound, based on 4-methoxy-6-ketomorphinan, and on 4-methoxymorphinan were synthesized and biologically evaluated for their antinociceptive activity. The biological activity of these compounds were compared with the 3-deoxyopioids. The N-H, N-formyl and N-methyl analogs were examined. The N-methyl-4-methoxy compounds were found to be more potent antinociceptive agents than the comparable 4-hydroxy molecules. Thus, 4-methoxy-6-ketomorphinan was found to be three times more potent than morphine as an antinociceptive, as was 3,4-dimethoxymorphinan.